This invention relates to liquid level indication devices.
There is a need for improved liquid level indication devices suitable for use in nuclear reactors and other hostile environments (e.g., corrosive and/or high radiation environments) subject to high temperature (e.g., 300.degree. C.) and high pressure (e.g., 1000-2000 psi) conditions. One conventional level sensor used in such environments is a rod along which a plurality of thermocouple-based sensors are positioned. Devices employing buoyant floats have also been attempted. For example, U.S. Pat. No. 4,870,862 discloses a device having an internally-pressurized titanium float, in which a magnetically permeable material such as iron has been inserted. Electro-magnetic coils surrounding the chamber in which the float travels provide an indication of the height of the float.